Method of coating metallic surfaces.



- muflie maybe opened without danger of ex-'-' CHARLES J. KIRK, OFCASTLE; PENNSYLVANIA.

A METHOD OF COATING METALLIC SURFACES.

No Drawing.

Specification of Letters latent.

Patented Oct. 12, 1909.

- Application filed May 28, 1908. Serial No.435,5 46.

To all whom it may concern:

Be it known that I, CHARLES J. KIRK, of

New Castle, in the county of Lawrence and State of Pennsylvania, haveinvented a certain new and useful Improvement in.

the metal to be protected with zinc flue-dust and then depositinga'metal on the surface produced by. the amalgamation of the zinc fluedust.

Heretofore metals have been coated with zinc, tin,- and other metals bypassing the metal .to be coated through a molten bath ofthe metal ofwhich the coating is composed. Metals have also been coated bydepositing the zinc or other metal electrolytically and they have alsobeen coated by what is known as the sherardizi'ngprocess I will nowdescribe my Invention so that others skilled in the art may employ thesame.

In the practice of my invention I first sherardize the metal to becoated. This may be done by packing the metal to be coated'inwhat isknown as zinc flue dust, which contains-about ten per cent. of oxid ofzinc, and then placin the metal and the zinc flue dustin a suita lemuflie from which the airis excluded and then subjecting it to heat fora suflicient length of time to. cause an amalgamation of the zinc withthe metal to be coated. The mufiie is then allowed to cool and thesherardized metalis withdrawn. Or the flue dust may be mixed with wateror oils and powdered charcoal to form a liquid or semi-liquid mass ofpaint or compound'which is then applied-to the surface of the metal tobe sherardized either by dipping the metal in a bath of the compound orthe same. The metal so painted or coated is then placed in a muflle andsubjected to heat the necessary length of time after which the plosionand the metal is withdrawn and allowed to cool. I have-discovered thatthis sherardized-surface forms a base upon which tin, zinc, or othermetal may be deposited by passing the sherardized metal through a moltenbath of the metal used to formthe coating, and owing to its peculiarqualities it causes an adhesion or amalgamation of the molten zinc, tin,or other metal far greater than would exist between the original surfaceof the metal and such coating, so much so that a coating having new andcharacteristic properties is produced on the surface of the sherardizedmetal. The second step of my process therefore consists in dipping thesherardized metal in a molten bath of zinc, tin, or other metal in theusual manner employed in galvanizing, tinning and coating metals in amolten bath. As the metal is wlthdrawn from the bath the excess ofmolten metal may. be wiped off in the usual manner. The metal when soremoved from the bath is ready for use or it may be subjected to variouspolishing and finishing steps well'known in the art.

The advantages of my invention are that as by the sherardizing step anamalgamation of the zinc, and the metal to be coated, takes place, so inthe dipping step an amalgamation of the sherardized surface and themetal composing the molten bath takes place, producing adurable,amalgamated surface on the metal to be protected.

Having thus described my invention, what I claim and desire to securebyLetters Patent is:

sisting in sherardizing the metal to form a primarycoating and thendipping. the article so treated in abath of molten metal capable withthe primary coating. by painting the surface of the metal with M. ARTHURKELLEn,

M. A. EARTH.

1. The method of protecting metal, con-'

